Improvement in screws



v enable those persons who are skilled in the art, to make cording to my invention.

. after it is brought to the required shape, and before it l to the form shown in g.. 2, by suitable dies or formers,

r.v WASHBOUR'NVE. o

r NEW YORK, N. Y.

Letters Patenti No.l 84,663, dated December 1, 186.8.

IMPROVEMENT IN SCREWS.`

The Schedule referxedto in these Letters Patent and making 4part of the same.

we y To all whom 'it may concern Bc it known that I, F. ksrreounnn, of No. 62 Reade street, in the cityand State of New York, have invented a new and useful Improvement in Bib and other Screws; andI hereby declare that the following is afull, clear, and exact description thereof, which will and use the same, reference being had to the accom panying'drawing, making part of this specification, in which drawing` l Figure l is an axial section of a bib-screw made ac-` Figure 2 is a cross-section ofthe head, as it appears is united to the shank of the screw.

Figure 3 is a plan view of the blank from which the head is struck up.

Figure 4 is a detailed view of the shank.

This invention relates to the construction of screws; and

It consists, among other things, in'making the head and shank in separate pieces, and afterwards uniting them by soldering or brazi'ng them together, the slot across the head being extended down into the top of the shank, soithat in turning the screw with a screwdriver, the implement will take hold of the slot in the shank, and consequently the liability of wrenching ofi"` the head will be avoided.

In fgrA l, I have shown a bib-screw made according to my invention; and in tig. 2, I have shown a detailed sectional view of the head only, before it is slotted.

The said head, when made` of wrought-metal, is formed or cut out, in the first place, tothe shape of y the blank shown in iig. 3, and is afterwards broughta recess, Cybeing, -in the same operation, formed in the under side, in a central position, to receive the top of the shank B. y

The blank from which the shank B is formed is attached to the head by inserting one end in the recess C, and soldering or brazing it t0 the head.

The screw-thread is formed on the shank after it is united to the head, but it may be formed previously, if preferred.

After the head and shank are iirmly united to each other, I cut a slot, D, across the top of the head, to

receive the end of a screw-driver, and I sink said slotdown until it intersects the slot C, and enters the upper end of the shank B a suflicient distance to enable the screw-driver-to take hold of the shank.

Bib-screws are no'w made by casting them, head and shank, in one piece; but screws so made are brittle, and liable to be easily broken, and a large percentage of metal is wasted in their manufacture. In addition to these disadvantages, their appearance is rough and coarse, compared with such as `are made of wrong-ht-A metal according to my invention. Whereas my improved screws are of v superior toughness yand strength,

and capable of more wear, and are less liable to break than those that are, cast in one piece.

Having thus described my invention,

What I claim as new, and desire to secure by Letters 

